1. Field of the Invention
The present invention generally relates to signal detection more particularly to the detection of a low frequency state of a communication signal.
2. Related Art
Various types of communication standards, such as universal serial bus (USB) 2.0 or USB 3.0 standards, may be used for communication between devices for tasks such as data storage, communications, printer/scanner connections, and other tasks. Data communication between such devices generally takes place using a variety of communication signals having a variety of signal states. For example, a communication signal may be in an idle state where little or no data is communicated, a low frequency state (e.g., a low frequency periodic signaling (LFPS) state during the performance of a handshake protocol) where devices are awakened or initialized and trained for features such as power management, or a high frequency state (e.g., a hi-speed (USB 2.0) state or a Super Speed (USB 3.0) state) where data is communicated at high data rates between devices.
However, detection of the different states of the data communication signals using existing detection techniques is often difficult. Accordingly, there is a need for an improved approach to signal detection.